And it was all a dream... Amenábar takes perhaps the biggest cliche in entertainment with both hands and runs with it, largely by simple repetition. His hero César (Noriega) keeps waking up, in a series of circles that are both concentric and overlapping, drawing you inexorably into his confusion. Is his face horribly disfigured or not? Is his girlfriend Sofia (Cruz) or Nuria? Why is he now accused of murder? And who is the mysterious "Eli"? All these will - more or less - be explained, though if truth be told, the ending seems rushed. It's as if the director fell in love with the convolutions of his story, rather than the resolution.
Up until then, however, it certainly has more than enough fine moments, and it's unlikely you'll be much ahead of the plot - unless, of course, you saw the Hollywood remake: Vanilla Sky starring Tom Cruise, with Cruz reprising her role. I can see the appeal; Cruise and Noriega have similarly rugged good looks [I can also understand why they changed the title, which'd be too close to Cruise's Eyes Wide Shut otherwise], though I sincerely doubt the new version brought much to the party. Remember the hotel scene in Total Recall, where Arnie tried to work out if his Mars trip was really happening? Imagine it extended to two hours. You may or may not take that as a recommendation, but despite a central character it's easy to dislike for shallow vanity, as far as messing with your head goes, this is intense and effective.